The present invention relates to a pressure measuring instrument, and more particularly to a piezoelectric pressure measuring instrument.
An object of the present invention is to provide a pressure measuring instrument for the measurement of the combustion chamber pressure in a cylinder of an internal combustion engine which is easy to install between a first wall extending radially outward from one axial end of a spark plug insert bore formed through an engine cylinder head and a second radially extending wall of a spark plug threadedly engaged in the spark plug insert bore.